Answer:
The first and second
Step-by-step explanation:
The first one is right 12/3=4
The second one is right 12*5=60
The third one is wrong 100-184=-84 not 84
Answer:
x = - 1, x = 1, x = 2
Step-by-step explanation:
The coefficients of the polynomial sum to zero, that is
- 1 + 2 + 1 - 2 = 0
This indicates that x = 1 is a zero
let x = - 1, then
- (- 1)³ + 2(- 1)² + (- 1) - 2 = 1 + 2 - 1 - 2 = 0
Thus x = - 1 is a zero
let x = 2
- (2)³ + 2(2)² + 2 - 2 = - 8 + 8 + 2 - 2 = 0
Thus x = 2 is a zero
The 3 zeros are x = - 1, x = 1, x = 2
Step-by-step explanation:
sina = -√3/2
=±1/2
Since, π<a<3π/2
cos a = -1/2
OptionB
Answer:
153
Step-by-step explanation:
i = square root of -1
i = √-1
(3+12√-1) (3-12√-1)
√a times √b = √ab
a√b times c√d = (a times c) √ (b times d)
9 - (36√-1) + (36√-1) - (144(√-1)^2) =
9 - 0 - (144 * -1) =
9 - 0 - (-144) =
9 - (-144) =
9 + 144 =
153
*** funny thing is if you put
(3+12i) (3-12i)
in a calculator
it works!
it gives you the answer 153
another way:
Expand the expression using
(a-b) (a+b) =
a²-b² :
3²-(12i)²
Simplify using exponent rule with same exponent
(a*b)^n =
a^n*b^n:
3²-12²* i²
Calculate the power:
9-144* i²
Rewrite by definition
i²=-1:
9–144×(−1)
Calculate the product or quotient: 9+144
Calculate the sum or difference: 153
Answer: 153
gathmath